[1][3] In Oregon, 17 or 18 people died as a result of the disaster, and it caused hundreds of millions of dollars in damage.

[1] The flood killed 19 people, heavily damaged or completely devastated at least 10 towns, destroyed all or portions of more than 20 major highway and county bridges, carried away millions of board feet of lumber and logs from mill sites, devastated thousands of acres of agricultural land, killed 4,000 head of livestock, and caused $100 million in damage in Humboldt County, California, alone.

[6][7] An atypical cold spell began in Oregon on December 13, 1964, that froze the soil, and it was followed by unusually heavy snow.

[5] Some of the worst mudslides occurred in the Mount Hood Corridor, and one man died in a mud and debris avalanche near Rhododendron that destroyed 15 houses.

[3] Other deaths occurred from drowning and electrocution, and one man died when the new John Day bridge collapsed.

Eventually, the flooding coupled with a loss of power led to the decision to evacuate patients to Salem General Hospital on Center Street.

121 patients were evacuated from Salem Memorial by hospital staff, doctors, ambulance crews, and the National Guard.

Salt Creek washed out 25 miles (40 km) of Oregon Route 58 and undermined the SP viaduct footings.

[11] Starting on December 21, intense downpours across Northern California caused numerous streams to flood, many to record-breaking levels.

Many communities of Del Norte and Humboldt counties suffered extensive power outages and were left isolated or cut off from the rest of the state for a period, including the region's larger populated areas around Humboldt Bay, such as Eureka and Arcata, despite the fact that those cities were located on higher ground and not in the path of raging rivers.

Riverside communities like Klamath, Orleans, Myers Flat, Weott, South Fork, Shively, Pepperwood, Stafford, and Ti-Bar were completely destroyed by flood waters; some of them were never rebuilt and none regained their former status.

[12] Crescent City, still recovering from the tsunami created by the 1964 Alaska earthquake only nine months earlier, also suffered from the floods.

[16] Just under 200,000 cubic feet per second (5,660 m3/s) of water flowed down the South Fork Eel River alone, causing severe damage along its entire length.

The flood caused the uncompleted Hell Hole Dam on the Rubicon River to fail, sending even more water downstream.

[7] In southwest Washington, rising rivers threatened Centralia and Longview–Kelso[1] and closed Interstate 5 and all railways at flooded Kalama for over a week.